Using data collected from the World Bank in February 2020, the website tradingeconomics.com ranked China according to its citizens’ ability to participate in selecting their government, freedom of expression, and access to a free media. Each in a small sample of 12 sources provided a ranking for China, where a rank of 0 is the lowest rank possible and a rank of 100 is the highest rank possible. These sample ranks were used to form a 90% confidence interval for the population mean rank of China. The result: (2.96, 9.36).

a. Give the value of the confidence coefficient for this small-sample interval. How should it be interpreted?

b. What t-value was used to compute the 90% confidence interval?

c. Provide a practical interpretation of the 90% confidence interval.